Glossary

A (alphabet bar)

acervulus

(pl. acervuli) Fruiting body of a parasitic fungus in the form of a small dish, in which asexual spores, conidia, are formed. It generally is formed just below the plant’s epidermis, that is ruptured when the acervulus is ripe to release its spores.

aciculate

Needle-shaped.

aecidium

Less often used equivalent for aecium.

aecium

(pl aecia). The second stage in the life history of rust fungi, Pucciniales.

Puccinia poarum: underside of a leaf with aecia

characteristically, the spores are produced in a chain

only under exceptionally quiet circumstances a picture like this can develop

aestivation

Summer dormancy; a period when an insect enters a state of immobility and lowered metabolism, analogous to hibernation.

Agromyzidae-type

Cephalic skeleton, typical for for the family Agromyzidae; in particular the anterior arm is simple, quite unlike in the Tephritidae or Drosophilidae.

Ophiomyia beckeri larvs: cephalic skeleton

Agromyzinae-type

The posterior part of the cephalic skeleton with three “arms”, which is characteristic for the subfamily Agromyzinae.

Agromyza anthtracina: cephalic skeleton

alate

(pl altae). The winged stage of aphids; opposite to aptera.

amphigenous

At/on both the upperside and the underside of a leaf; especially in parasitic fungi an important character.

B (alphabet bar)

basidium

(pl basidia). The spore-forming organ of the Basidiomycota on top of which, after meiosis, four spores are formed.

biguttulate

Conidia: with two oil drops.

binucleate

Said of hyphae cells containing two nuclei. In Basidiomycota almost all hyphae are binucleate. In Ascomycota binucleate hyphae occur only after fusion of two compatible uninucleate hyphen, as a preamble to sexual reproduction.
A binucleate tissue is called a dikaryon. It is a unique common character of Ascomycota and Basidiomycota, that for this reason are united in the subkingdom Dikarya.

bivoltine

Life cycle with two generation per year.

blotch mine

A mine that is not longer than three times its width; “Platzmine” in the German literature. Opposite to gallery or corridor mine. See also primary and secondary blotch mines.

boreo-alpine

Said of a species distributed over the more northern parts of Europe, at the same time occurring in the higher mountains.

brachyblast

Short lateral branch, like in Larix.

brachypterous

With more or less strongly reduced wings.

broadly polyphagous

Living on a number, taxonomically unrelated plant families.

C (alphabet bar)

caeoma

An unusual type of aecium, lacking a peridium.

caespitulus

(pl caespituli). Cluster of hyphae, conidiophores and conidia free on a leaf, often erupting through a stoma. It forms the anamorphic stage of a variety of fungi, grouped conventionally under the term Hyphomycetes. Instead of the technical term often the word “colony” is used.

callus

Tissue, formed after an injury, consisting of undifferentiated cells.

capitulum

Flower head; the inflorescence of Asteraceae and some other families that is so compact that it looks (and functions) like a single flower.

case

Transportable, tubular or rarely helicoidal structure, made of plant material, silk, rarely detritus, in which a larve lives and walks around, and from which it may make a fleck mine. Most often made byColeophoridae larvae.

cauda

A prolongation of the terminal abdominal segment in aphids. Its shape is diagnostic.

caulicolous

On the stem. (Most rust fungi occur on the leaves only, but some are also caulicolous.)

cephalic skeleton

Chitinous, X- or H-shaped structure in the “head” of Diptera maggots, on which the mandibles and chewing musculature are attached.

cephalopharyngeal skeleton

The formal term for the cephalic skeleton of Diptera larvae.

cf

In full: “confer”: compare.

chaetotaxy

The arrangement of the setae (“hairs”) in insects. The chaetotaxy is genetically strictly defined. The patterns are characteristic for families, genera and often species. Chaetotaxy especially plays a role in the identification of Lepidoptera larvae, in combination with the placement of the pinacula.

chasmothecium

chlamydospore

Chromalveolata

clavate

cleistothecium

(pl cleistothecia). Fruiting body , ascocarp, of the powdery mildew fungi, Erysiphaceae. They are globular, closed, and contain one or a few asci.

cocoon

Envelope made out of silk (and often other material, in particular frass) protecting a pupa.

Coelomycetes

Deuteromycetes that releases their spores from a fruiting body, either an acervulus (Melanconiales) or a pycnidium (Sphaeropsidales). It is an artificial grouping, purely based on the form, not on a systematic relationship.

coiled frass

Characteristic arrangement of the frass grains, caused by the larva swinging its rear end slowly to and fro while eating, moving and defecating. This behaviour occurs only in some moth species.

Stigmella hemargyrella

colony

-> caespitulus

columella

(Literally: small column): rod-like central part of an ovary that has been destroyed by some smut fungi The columella is composed of both fungal and host material (McTaggart ao, 2012a).

Sphacelotheca hydropiperis

composite leaf case

One of the types of case that is distinguished within the family Coleophoridae.

conidiodoma

(pl conidiodomata). Specialised structure upon or within which conidia are formed.

conidiophore

Simple or branched fungus hyphae on which one or more conidia are formed.

cremaster

cupulate

D (alphabet bar)

deuterogyne

In some species of gall mites (Eriophioidea), mainly in species living on woody plants, next to the normal type of females (protogynes) another type occurs, deuterogynes. They are better adapted to unfavourable conditions; often deuterogynes form the hibernation or dispersal stage.

Deuteromycetes

(= Deuteromycota = Fungi Imperfecti).Fungi generally alternate between an asexual stage, called the anamorph, and a quite different sexual stage, the telomorph. In many cases only one of the two stages is known, or the relation the two has not yet been established. Often the telomorphs occurs rarely, maybe not at all. Sometimes several anamorphs belong to a single telomorph.

Because fungal classification is based in the telomorph, the position of the unconnected anamorphic fungi is unclear; the used to be placed in the artificial group Deuteromycetes. Presently, molecular techniques have given many Deuteromycetes a place in regular fungal classification.

The Deuteromycetes used to be divided in several equally artificial groups. They still have a practical use when it comes to identification of anamorph fung: Hyphomycetes and Coelomycetes the latter in turn divided in Melanconiales and Sphaeropsidales.

dorsal

downy mildews

Drosophilidae-type

E (alphabet bar)

ecdysis

The final moult, the one in which an imago emerges from its pupa.

epidermal mine

Mine that (almost) entirely is restricted to the epidermis; always has a silvery appearance.

epidermis

The outermost layer of cells of the leaf, in fact, the skin of the leaf. The epidermis consists of somewhat flattened cells that do not contain chlorophyll. The outside wall of the epidermis cells is thickened: the cuticle.

epipharynx

Membraneous extension of the upper lip (labium), in fact its outwardly protruding inside. The epipharynx may bear a number of specialised flattened setae.

Zeugophora sp., from Medvedev & Zajcev (1978a). From the top down: the clypeus, upper lip (labium) and the epipharynx with specialised, flattened, epipharyngeal seta

epiphyllous

At/on the upperside of a leaf.

erineum

(pl erinea). Gall in the form of an abnormal hair cover, often with elongated, strongly curled or apically swollen plant hairs. Erinea are caused by gall mites.

Aceria pseudoplatani

exit slit

Many species pupate outside their mine. Before vacating the mine they use their mandibles to cut a slit in the epidermis; this slit mostly has a very fixed, more or less semicircular shape. Often it is species-specific whether the slit is made in the upper or lower epidermis.

exuvium

F (alphabet bar)

feeding punctures

Pin-sized puncture made by an agromyzid female with her ovipositor in the surface of leaf. She subsequently drinks from the extruding sap. Males, not having an ovipositor, drink from the punctures that the females have made.
A single fmale can make many tens of punctures in a leaf. When Agromyzidae are a pest it often is not because the
mines made by the larva, but because of water loss of the leaves caused by the feeding punctures. Next to Agromyzidae also Scaptomyza (Drosophilidae) species use their ovipositor to make feeding punctures.

Phytomyza podagrariae: feeding punctures

femur

An insect foot has the following joints: first a short coxa (“hip”), a generaly kong femur (“thigh”), a gnerally long tibia (“shin”) and finally some short tarsi.

fibrosin bodies

Strongly refractive particles in the conidia of some true mildews. They somewhat remind of shards of glass.

Podosphaera fugax

filament

A mass of conidia, extruded as a white thread

Eudarluca caricis, a parasite in the telia of a rust fungus

fleck mine

Full depth blotch, not containing frass, and invariably with one, more or less central, usually circular, hole. Made by a larva (usually a Coleophora that operates from the outside. The larva first bites the hole in the epidermis, then from that point it eats away as much leaf tissue as it can reach without fully entering the mine.

Coleophora serratella: a typical fleck mine, mined out via the opening, no possibility that frass could be left in the mine.

frass

Excrements of phytophagous insects.

frontal appendage

Finger-shaped unpaired appendage in front of the head in several Agromyzidae larvae.

Phytomyza ilicis

full depth

Mine where (almost) all the leaf tissue between upper and lower epidermis has been eaten away.

fundatrix

(pl fundatrices).Hibernated, female aphids that start a new colony in spring. The fundatrix has hatched from a fertilised egg. Her feeding activity may induce gall formation.

green island

An autumn phenomenon. The presence of an occupied mine in a dying leaf can block the yellowing process. The tissue around the mine keeps its original green colour, even when the leaf already has fallen to the ground.

H (alphabet bar)

helicoidal

Wound like a snail’s shell.

hibernaculum

Construction in which an insect hibernates.

holocyclic

The life cycle of some insect groups, like aphids and gall wasps consists of an alternation between a sexual generation and an asexual one. Such a complete cycle is called holocyclic. Some, related species however may have an abbreviated cycle: either only a sexual stage, or continuous asexual reproduction; this situation is called anholocyclic.

hypermetamorhosis

When two successive larval stages differs much more strongly that normally is the case, and the impression is given of an extra metamorphosis, one speaks of a hypermetamorhosis.
A striking example is given by the transition made by Gracillariidae from a sap drinking stage to a tissue feeding one, that moreover is accompanied by major modifications in body stature.

Hyphomycetes

Deuteromycota that form their spores on conidiophores that are not located on or in a fruiting body. It is an artificial grouping, purely based on the form, not on a systematic relationship.

hypophyllous

At/on the underside of a leaf.

I (alphabet bar)

imago

(pl imagines). The adult, sexual and winged, insect.

indumentum

The hair cover of a plant.

inner mine

After the larva has made a mine in the upper epidermis it makes, within this mine, a new one in the palissade parenchyma. Unique behavious, known only from Phyllonorycter corylifoliella. A somewhat comparable behaviour is seen in the larva of Phytomyza ilicis.

inquiline

An animal that lives in the nest, colony, or burrow and another animal species. In connection with this site generally a larva that lives in, and feeds on, a gall that has been caused by the actual galling insect. The severity of the ensuing competition varies strongly. Galls that are co-occupied by one or more inquilines often have an abnormal appearance.

Misshapen gall of Pontania proxima; the gall was disfugred because of the presence of several inquiline larvae tunnelling in the fleshy wall.

instar

There generally are three to five stages in the larval life of an insects, called instars, each one ending with a moult.

integument

The “skin” of a larva or imago.

interparenchymatous mine

A rather uncommon type of mine, occurring in the Agromyzidae. The mines are made in the lowest part of the palissade parenchyma and/or the upper part of the sponge parenchyma. Interparenchymatous mines typically are yellow-green in colour.

lateral

lobe case

M (alphabet bar)

maggot

The order Diptera consists of two groups: midges (Nematocera) and true flies (Orthocera). Larvae of he relatively primitive Nematocera have a slender and a chitinised head. Larvae of the true flies have a much more compact build; moreover the head, with almost all of its organs has been almost completely reduced: maggots.

mala

Small lobe, next to the mesal side of the maxillary palp (techically the fused galea and lacinia of the maxillae).

Zeugophora spec. from Medvedev & Zajcev (1978a): Maxilla, with to the left the maxillary palp and tot the right the mala; bottom right the tip of the underlip.

Malpighian tubule system

Excretion organs, in function comparably with our kidneys. As is indicated by its name, it consists of number of thin tubules in the abdomen.

mandible

Insects have two pairs of jaws: the maxillae, situated deeper in the mouth and with a complicated structure, and the mandibles, large, built of one piece, that serve for biting. In maggots the mandibles are lost, but the mandibles ars still there, and sometimes are useful for identifications.

Cerodontha incisa

median

On, of close by, an imaginary length line over the middle of the body.

Melanconiales

Deuteromycetes, subgroup Coelomycetes, that form their spores in an acervulus. It is an artificial grouping, purely based on the form, not on a systematic relationship.

mesal

Seen from the median line.

mesonotum

The dorsal side of of the mesothorax, i.e. the middle segment of the thorax.

mesospores

The large genus of rust fungi, Puccinia, is characterised by having two-celled teliospores. However, a, generally quite small, minority of the spores is unicellular; they are addressed as mesospores.

metanotum

The dorsal side of of the metathorax, i.e. the third segment of the thorax.

monophagous

Living on a single plant genus. If this species contains, within the distributional area of the parasite, many species, while the parasite lives on just one or a few of them, one can call the parasite “narrowly monophagous”.

mouth angle

The anterior opening of the cases of Coleophoridae larve sometimes are perpendicular to the length axis of the case, but in many species it forms a more or less oblique angle. This is called the mouth angle.

multivoltine

Having a large number of generations per year; in warmer regions having one or more generations also during the winter. There is only a short period of pupal rest.

nymph

O (alphabet bar)

oculus

Thin-walled part of the wall of the tip of an ascus, through wich the spores are released.

Podosphaera myrtillina var. myrtillina: ascus with at the upperside in the foto the oculus

oligophagous

Feeding om a restricted number of plant genera, all of the same plant family.

oospore

Thick-walled cell, derived from a fertilisation, embedded in the host plant tissue. Their biological function mostly is of a resting spore, in particular for hibernation.

ovipara

(pl oviparae).Aphids generally during the summer pass through a number of consecutive generations of viviparae, females that asexually produce living young. The final generation that is born in autumn is different, consisting of males and females that, after being fertilized, lay eggs that enable the population to hibernate. These egg-laying females are called oviparae.

oviposition

The deposition of the egg(s).

oviposition scar

In cases where the egg is deposited within the plant tissue, this is done either by means of an ovipositor, or by biting a hole in the leaf (mostly a thick vein). This causes a wound reaction of the plant, that may remain long after the mine has been vacated.

Fenusa dohrni: mines, each one with an oviposition scar.

Orchestes fagi, a weevil. A female, that has no ovipositor, gnaws a hole in the underside of the midrib, and deposits an egg in the wound.

ovipositor

In order to deposit her eggs inside the tissue of a living plant the female needs relatively much force. Often the terminal segments are adapted to the job, mostly by being heavily chitinised and hardened, like for example in the Agromyzidae, Cecidomyiidae, and Tephritidae. In the sawflies, Tenthredinidae, the ovipositor has taken the shape of a little saw.

ovisac

A sac, made out of wax threads or silk, containing eggs.

P (alphabet bar)

palissade parenchyma

A layer of columnar cells (generally one to three cells thick) that form the upper layer of a leaf, just below the epidermis. This section of the leaf is particularly adapted to photosynthesis, and contains the highest number of chlorophyll grains. (Not all plants have a palissade parenchyma, like ferns and grasses.)

pallium

Literally “mantle”, two flaps that in some Coleophora species hang on the anal end at either side of the case; in some species, like C. kuehnella the entire case may be covered.

Coleophora ibipennella

pappus

The “plume” on top of the fruit of most Asteraceae; Also to total of them within a flower head.

parasitoid

Many insects place their egg in or on the egg or larva of their prey; the larva that emerges slowly devours the host larva. To call this behaviour parasitic is not justified, because real parasites, like fleas or lice, need to keep their host alive, rather than to kill it. Therefore this type of insects is called parasitoids. For plant parasites most parasitoids belong to the order Hymenoptera.

pedicel

Generally: stalk; applied in particular for the stalk of a teliospore.

peduncle

A stalk supporting an inflorescence

perforate mine

An interparenchymatous mine, from where repeatedly pieces have been eaten out of the “roof”, i.e. the palissade parenchyma. At first sight this type of more looks like a piece of leaf diseased by some fungus. When held against the light such a mine has a perforated appearance.

Phytomyza heracleana: example of a perforate mine.

peridium

The wall of a sporangium or other spore-forming organ.
The aecia of rust fungi originally are a hollow bladder, the when ripe burst at the tip; the wall, i.e. the peridium, is forming then a characteristic fringe.
The term is applied also to the wall of a cleistothecium.

perithecium

Special type of ascocarp: flask-shaped, opening with a pore.

petiole

The “stalk” of a leaf.

Phytomyzinae type

Rear part of the cephalic skeleton with 2 “arms” (character of the Agromyzidae subfamily Phytomyzinae).

The cephalic skeletons of the two Agromyzidae in comparison: Agromyzinae (left) and Phytomyzinae (right)

phytophagous

Feeding on plants.

pinaculum

(pl pinacula). In Lepidoptera larvae: small chitin plates, often coloured brown or black, on which long setae (“hairs”) are inserted.

pistol case

One of the types of case that is distinguished within the family Coleophoridae.

plasmodium

A mass of protoplasma containing a number of nuclei, not separated by cell walls.

plurivoltine

Several generations per year.

polyphagous

Living on two or more plant genera belonging to different families. If these families are closely related, one can speak of “narrow polyphagous”, in the opposite case of “broad polyphagous”.

posterior

To the rear end; opposite to anterior

powdery mildews

prepupa

The final larval stage of sawflies often differs considerably from the preceding stages: there are differences in the shape of the mandibles, and often the prepupa is entirely white of bone-coloured. At this stage feeding as stopped and the larva is remarkably sluggish.

Scolioneura vicina: prepupa

primary blotch mine

Blotch, caused by the larva feeding from the centre in all directions.

primary feeding lines

Arrangement of remnants of green leaf tissue in a pattern of parallel lines of made by the mowing movement of an agromyzid larva that is grazing away the leaf tissue while lying on its side.

Trypeta artemisiae: primary feeding lines

primary host plant

Many aphid species go through an alternation of hostplants. In spring a fertilised female then starts a colony on a, generally woody, primary host plant. After spring, when the nutritional quality of the host plant’s juices is diminishing, migration takes place to a secondary, non-woody, host plant.

prolegs

Larvae of Lepidoptera and Tenthredinidae (sawflies) not only have three pairs of thoracic feet, like all insects, but also several abdominal segments have a pair of appendage that look like feet, and have the same function. Usually they have a row or circle of crochets at their tip. A less formal term for prolegs is abdominal feet.

Epermenia chaerophyllella: larva with thoracic feet and prolegs

pronotum

The dorsal side of of the prothorax.

prosternum

The ventral side of of the prothorax.

prothorax

The first, foremost, segment of the thorax.

protocedium

In sawflies it sometimes happens that the oviposition scar functions as a gall for the very youngest stage of the larva; once the scar has been eaten out the larva starts living free on the plant. The scar then is addressed sometimes as a protocecidium, “predecessor of a gall”.

protocecidium of an unknown sawfly on Alchemilla; upperside

underside; the protocecidium was already vacated

proximal

Nearest, nearest to the centre.

pseudocerci

A pair of short appendages at the terminal segment of some sawfly larva.

pterostigma

(Often just stigma). A cell in the venation of an insect wing, always at the frontal margin and not far from the tip, that mostly is thickened and darkly coloured.

pulvinate

Cushon-shaped.

pupal chamber

Cell or small blotch, often separated from the main mine, where pupation takes place. More or less distinct part of the mine, in which the pupa(rium) is waiting.

puparium

The barrel-shaped “pupa” of a fly ( not of a midge: midges generally have a true pupa). It merits a word for its own because, although it looks like a pupa, it essentially is the last dried larval skin, with the true pupa inside. Only at rare occasions it is possible to see the real pupa within the puparium: foto below.

Agromyza albitarsis

Phytomyza agromyzina: pupa; in the background the remnant of the puparium.

pycnidium

(pl pycnidia). Cavity in the plant tissue, in which asexual fungal spores (conidia) are formed, and ejected through a pore. Contrary to acervuli, pycnidia are situated deep in the plant tissue, and from the outside recognisable only by their opening.

Q (alphabet bar)

R (alphabet bar)

rachis

Main axis of a composite leaf, or of fern leaf.

rostrum

In aphids the lower lip (labium), that ahs been transformed into a hollow tube. Through this tube the stylets can be pushed out. The stylets, strongly modified mandibles and maxillae, pierce into deeper layers of the plant’s tissue and bring up the sap.

rust fungus

S (alphabet bar)

sclerite

Slab of chitin

sclerotium

(pl sclerotia). A hard, dry of fungal tissue that is resistant to unfavourable conditions and may remain in a resting state for an extended period.

secondary blotch mine

Blotch that originates when a gallery is so densely wound that the separating walls wholly or partly disappear (are eaten away). Sometimes the remnants of the walls are visible as secondary feeding lines; more often the frass pattern indicates a secondary blotch.

secondary feeding lines

Arrangement of remnants of green leaf tissue in parallel lines, caused either by the formation of a secondary blotch, or, more typically, by the larva shifting its position while feeding (Hering, 1927a; Hendel, 1928a).

Nemorimyza posticata

seed case

One of the types of case that is distinguished within the family Coleophoridae.

septum

(pl septa). Dividing wall, e.g. in a fungal spore or hypha. Often a septum contains a pore that enables some regulated connection between the protoplasma at either side. Hyphae without septa are called aseptate.

seta

(pl setae). The “hairs” of arthropods differ in their structure fundamentally from those of mammals, and therefore are called setae. Thick and heavy setae also are designated as bristles.

sheath case

One of the types of case that is distinguished within the family Coleophoridae.

siphunculus

(pl siphunculi). A pair of rod-like appendages on the abdomen, an exclusive character of the family Aphididae, aphids. The exude a viscous liquid containing mainly excess sugars – to obtain the necessary amount of amino acids, aphids need to digest much liquid, and ingest much more sugars than needed. Shape, sculpture and even colour of the siphunculi are diagnostic. In some instances they are reduced to no more than flat pores.

smut fungus

sorus

(pl sori). A compact cluster of spores forming fungal tissue, like an uredinium or telium.

spatula

Mature larvae of gall midges often have ventrally on the thorax a chitinous rod, at the front end ending in a small fork.

Most of the spatula lies internal, just below the epidermis; only the part above the stippled line is external.

spatulate leaf case

One of the types of case that is distinguished within the family Coleophoridae.

spermogonium

(pl spermonia). First stage in the life cycle of the Pucciniales. It are mostly orange-coloured pycnidia the at maturity exude liquid.

Puccinia festucae on Lonicera periclymenum

Puccinia festucae

Sphaeropsidales

Deuteromycetes, subgroup Coelomycetes, that form their spores in a pycnidium. It is an artificial grouping, purely based on the form, not on a systematic relationship.

spiraculum

The exit of the tracheal system. To prevent the entrance of unwanted material the openings have a complex structure. Fly larvae have two pairs of spiracula, one pair just behind the ‘head’, another pair near the end of the abdomen. In Agromyzidae the spiracula mostly are stalked. The tracheae are connected with the outside world through three or more fine openings, each in a so-called papilla, on top of a spiraculum.

Amauromyza labiatarum: anterior and posterior spiraculum, lateral

spongy parenchyma

The lower half of the thickness of a leaf, consisting of loosely arranged cells with large air spaces between them. This tissue functions essentially for the exchange of gasses: supply of carbon dioxide and the removal of oxygen.

stroma

systemic

Most fungal infection are local. However, in some species the mycelium pervades the entire plant body. This has important biological implications: the fungus may be dispersed by infected seed, and the fungus may hibernate in the below-grond pats of the plant.

T (alphabet bar)

tarsi

The most distal part of an insect foot, consisting of a number of tarsi. The last one generally end in one or two tarsal claws and and attachment pad.

teleutosorus

(pl teleutosori). Currently unusual equivalent of telium.

teleutospores

Less currently used synonym of teliospores.

telium

(pl telia). The fourth stage in the life cycle of rust fungi, Pucciniales. Generally they appear after the uredinia, and are darker in colour.

Puccinia ptarmicae: a telium under the microscope

telomorph

The sexual stage of a fungus (contrasting with anamorph). Often also spelled as teleomorph.

tentiform mine

Essentially an upper- or (more commonly) lower-surface blotch mine, usually made by a Gracillariidae larva. The larva lines the interior of the mine wit silk; the silk gradually shrinks, causing the mine to bulge. Because the mine is not full depth both sides of the leaf behave differently then. The non-eaten leaf tissue because of its stiffness bulges up relatively little; the epidermis of the other side of the mine contracts much more strongly. Depending on the species one longitudinal fold may develop, or several lesser folds, or even a multitude of very fine folds.

Tephritidae type

Characteristic form of the cephalic skeleton.

Acidiia cognata larva: cephalic skeleton

thorax

The body part of an insect between head an abdomen, that in the larval stage (generally) bears feet, and in the imago (generally) also wings.

tibia

An insect foot has the following joints: first a short coxa (“hip”), a generaly kong femur (“thigh”), a gnerally long tibia (“shin”) and finally some short tarsi.

trichome

Hairs of plants, and also their modifications in an erineum, are fundamentally different from the hairs of mammals. In the technical literature they therefore often are addressed as trichomes.

tubular leaf case

One of the types of case that is distinguised within the family Coleophoridae.

tubular silken case

One of the types of case that is distinguised within the family Coleophoridae.

V (alphabet bar)

vagrant

Living freely on the leaves; phrase used in particular for gall mites.

ventral

At the belly-side, seen from below.

ventral ganglia

The neural system of insects consists of the brain, connected to a ring around the oesophagus, which in turn connects to a ventral strand along the whole of the with swellings, called ganglia, in each of the segments. It often is conspicuous in Nepticulidae larvae

Stigmella plagicollella

ventral plates

Mostly brown plates at the ventral side (rarely also at the dorsal side) in some larvae of the genus Ectoedemia; they only occur in the youngest stages.

vivipara

(pl viviparae). Female aphid that, without fertilisation, produces living young. Often viviparae are wingless (“apterae”), but they may winged as well (“alatae”). Usually a species during summer has a number of generations of viviparae. In autumn male and female aphids are born. The fertilised females (the “oviparae”) lay eggs by which the population passes the winter.

An alate vivipara

W (alphabet bar)

window feeding

Damage to a leaf, caused by a larva that locally consumed all leaf tissue except either the upper or the lower epidermis, leaving a conspicuous, very transparant “window”. Window feeding can easily be mistaken for a mine; see the little chapter about “pseudo-mines”

Y (alphabet bar)

yeast

One-celled fungus, that reproduces asexually by sprouting or cell division. Some groups of fungi are permanently in this stage, but many Ustilaginomycotina, and also the species of Taphrina pass their anamorphic stage as yeasts.

youth case

Coleophoridae larve in self-made tubes. Som species are capable to enlarge the tubes in pace with their growth,
but other species once of twice have to construct a new one. The first tube then often not only in size but also in shape differs appreciably from the later one(s).